In the design of gas turbines a number of contradictory factors render a perfect design difficult to accomplish. For instance, one often encounters concentric tubular walls which are subjected to gases of extremely different temperature, so that expansion and contraction takes place, particularly when the turbine is brought from a cold condition to a hot operating condition. Thus, the different rates of expansion and contraction bring about geometric relationships that change considerably and make it difficult to seal one section of the turbine from another to prevent leakage of gas between two portions of the turbine. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a turbine seal capable of preventing leakage despite extreme differences in expansion and contraction of adjacent turbine elements.
Another object of this invention is the provision of a seal between concentric tubular elements of a turbine, which seal extends radially and is capable of good sealing despite axial and radial changes in the distance between the elements.
A further object of the present invention is the provision of a sealing system for use in a turbine, which system is simple, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
It is another object of the instant invention to provide a turbine seal which functions well and which is not destroyed by exposure to high-temperature gases.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.